Known in the art are methods of manufacturing twisted wire products, such as ropes and cables, comprising winding of wires and laying the wound layers of wires over a core (here and in what follows, the term "core" is used to denote that portion of the product which is inside a wound layer) and applying compression to the partly finished product with the aid of reducing means so as to cause plastic deformation thereof with a view to imparting thereto the desired shape and size (cf. USSR Inventor's Certificate No. 55,676; Cl. D07B 1/06 and British Pat. Nos. 794,411, and 794,412; Cl. 83/4).
According to the known methods, all the wires to be used for manufacture of the product are tightly laid into their position inside a circumference having in cross section a contour of the product to be made, and are in contact with one another along the generating lines. When compression is applied to such products, the wires of the outer layer, acting along the periphery upon each other, form a tightly compressed circular layer, which prevents the compression force from being transferred from the periphery of the product to the core thereof. As a result of this disadvantage the core of the product does not undergo plastic deformation sufficient for filling air spaces within it with the metal of deformed wires, which lowers the strength of the finished twisted wire product.
To obtain a sufficient degree of deformation and hence better filling of air space within the core with the metal of deformed wires, it is necessary to increase the compression force, which, in turn, entails an increase of the equipment capacity, and makes the compression process more complicated.
Such measure, however, as limited by the safety factor of the deformed outer layer. If even the compactness and integrity of the outer layer are preserved, the deformation of the product over its cross section, irrespective of the increase of the compression force, proceeds not uniformly from the periphery towards the core, which affect the strength and durability of the product.
Known in the art is also the method of manufacturing twisted wire products, such as ropes and cables (cf. U.S. Pat. No. 3,778,993; Cl. 57-145) comprising winding and laying wires over the core so as to form a wound layer, applying compression to the partly finished product in order to cause its plastic deformation for the purpose of imparting to it the desired shape and size. The wires of the layer being wound are so laid that part of them protrude above the adjacent wires of the same layer.
When compression is applied, the protruding wires are forced to wedge between the adjacent wires, which diminishes the initial deformation force. However, because of the excess metal resulted from the deformation of the wires, the outer layer takes a shape of a tightly compressed circular layer, which in the end, as indicated above, results in the insufficient strength of a twisted wire product and other disadvantages.
On the other hand, when protruding wires are forced in between the adjacent wires, not all the wires are deformed uniformly: the more deformed are protruding wires, and the less deformed are wires adjacent to them.
Irregular deformation of the wires leads, in the course of the use of the product, to their irregular wear and to a rapid spoilage of the more deformed wires whereby lowering reliability and the durability of the finished product.
In comparison with the prior arts the above method when applied for manufacture of a product having the same size, necessitates the increase of the ratio between the size of wires of the wound layer and that of the core. This entails the increase in the number of standard sizes of the wires used for manufacture of some products, and also affects reliability thereof. The principal object of the present invention is to provide a method of manufacturing twisted wire products having a high reliability and durability.
Another object of the invention is to provide a method of manufacturing twisted wire products, wherein the process of winding and laying wires on the core ensures a uniform deformation of the product over its cross-section when it is subjected to compression.
Still another object of the present invention is to provide a method of manufacturing twisted wire products wherein after compression there is provided a practically uniform deformation of the wires of the outer layer.
A further object of the present invention is to provide a twisted wire product, such as a rope, with wires of the outer layer, being able to relatively shift without deforming the product shape.
A still further object of the present invention is to provide a twisted wire product such as a rope, having a minimum number of the wire sizes.